Related Experiment Video
Updated: Aug 11, 2026

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
Published on: May 10, 2018
Transfer-RNA, magnesium and the formation of ternary complexes by eukaryotic initiation factor eIF-2
1Department of Biochemistry, University of the Witwatersrand, Johannesburg, South Africa.
Abstract:
The likely concentrations of free magnesium ions in assay systems measuring ternary complex formation with the eukaryotic initiation factor eIF-2 and the exchange of bound GDP have been calculated. Contrary to the suggestion of Roy et al. (Biochem. Biophys. Res. Commun. 146, 114-120) amounts of added tRNA are unlikely to sequester sufficient magnesium ions to affect significantly their role in the assays. There seems little correlation between methionyl-tRNA added and the extent of ternary complex formation in published data other than that expected from mass action. In vivo the concentration of methionyl-tRNA is probably greater than or equal to that of eIF-2 which is shown to be necessary for efficient functioning of the initiation factor.
Related Concept Videos
Ribosomal RNA Synthesis
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Transfer RNA Synthesis
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Improving Translational Accuracy
Initiation of Translation
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
General Transcription Factors
Initiation of Translation
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...

